Characteristic of interface effect in Cu–C60 granular films

Abstract

In this letter, Cu–C60 granular film is prepared with coevaporation method at room temperature. The conductance of the film is measured by in situ method, and its microstructure is characterized by transmission electron microscopy. The charge transfer from Cu to C60 is investigated with Raman spectroscopy. The results indicate that the sample has the uniformly granular microstructure. The interaction between C60 and Cu at the Cu–C60 interfaces, which significantly affects the orientational order–disorder phase transition of C60 and induces the phase transition of C60 in the temperature range from 219 to 248 K. The mechanism of the characteristic of such phase transition is discussed.